Quickly set up a measurement setup with analog inputs
Universal analog inputs are an advantage for many measuring tasks. Changing measurement tasks, multi-purpose measurements, different sensor types or fault analyses can be carried out with one device. However, a few features should be taken into account when making a selection.
Universal analog inputs are an advantage for changing measurement tasks. A wide variety of measuring applications, multi-purpose measurements or changing input signals can be implemented with one measuring device.
Typical applications for universal analog inputs
For many applications, it is an advantage if the measurement setup can be set up or reconfigured quickly. This includes measurements in the laboratory, tasks in research and development or fault analyses in industry. In the case of tests during development, the tasks can change at short notice and the measuring channels have to be reconfigured. Universal analog inputs are also advantageous for fixed installations, such as process monitoring, if different measured variables such as temperature, pressure and a voltage signal are to be recorded simultaneously. The different signals from thermocouples, resistance thermometers as well as voltage and current signals can be connected directly to the measuring device; external transmitters are not required.
What is important for universal analog inputs
Galvanic isolation of the inputs: Unwanted interference between the measurement inputs can occur during measurements. To prevent this, the inputs are electrically isolated. This prevents mutual interference.
Avoid ground loops: With measuring devices and sensors, low-frequency interference signals and equalizing currents caused by earth loops can distort the measurement signals. For this reason, each analog input should have two separate input terminals (differential inputs) without a common ground.
Sufficient measuring accuracy: The resolution and measurement accuracy of analog inputs is crucial for the quality of the results. For example, if the resolution is too low, small changes in measured values can lead to undesirable "step effects" in the measured value display and emerging trends can be overlooked as a result.
Internal linearization: The linearization functions for all common sensor types should be stored in the measuring device. For example, with a Pt100, the measured temperature values are displayed directly without the user having to worry about deriving them from the measured resistance values.
Measuring device and software support for universal analog inputs
The Loggito Logger - has either four or eight universal, differential analog inputs that can be configured for the connection of voltage, current or thermocouple signals. With the RTD versions, it is also possible to connect all common resistance thermometers such as Pt100 or Pt1000 in 2-, 3- and 4-wire technology. The analog inputs offer a resolution of 24 bits and have a measuring accuracy of 0.01% of the measuring range end value for voltage, current and resistance measurements.
The software ProfiSignal 20 supports the control of measured values even with multiple signal curves. Units such as pressure, temperature and voltage can be displayed simultaneously in a diagram using several Y-axes. The DataService configuration program is used to set up the measurement and control channels from the PC.